View Full Version : Lottery numbers with probability
kristenc812
Oct 9, 2008, 06:57 AM
I'm having trouble with this math problem. I have the answer, but I don't know how to get to the answer.
**In a New York State daily lottery game, a sequence of 5 digits (not necessarily different) in the range 0-9 are selected at random. Find the probability that all 5 are different.**
The answer is .3024. What is the process to get that answer? I'm having trouble because I don't know how to calculate it so that the numbers are different. Thanks in advance! :)
ISneezeFunny
Oct 9, 2008, 07:10 AM
__ __ __ __ __
five places.
in the first spot, you have out of 10 numbers (0 - 9) to choose from.
In the next spot, you now have 9 numbers to choose from, because the first one has taken one of the numbers.
In the next spot, you now have 8 numbers to choose from...
so on and so forth
10 * 9 * 8 * 7 * 6 = 30240 possible combinations.
kristenc812
Oct 9, 2008, 07:15 AM
Thanks for the post, but I don't need to know how many combinations are possible, but I need to know what the probability is to choose 5 numbers, all of them different. Like I said in my original post, the correct answer is .3024 or 1/3 (13/43).
ISneezeFunny
Oct 9, 2008, 07:17 AM
... I was throwing you a bone.
we don't do your work for you, we help you along.
I just gave you how many different combinations are available.
So the next step would be to find out how many combinations TOTAL is available.
10*10*10*10*10 = 100000
now, 30240/100000 = ?
kristenc812
Oct 9, 2008, 07:33 AM
Ok, thanks.. and I guess my second post came across wrong. I didn't mean for you to solve it.. I apologize if that's how it came across! I tend to over-think things and just assumed that the process was more complicated than it really was. Anyway, thanks for the help! Very valuable to this ADD brain of mine. :)